The present invention relates to an oscillating lawn sprinkler which is capable of being placed freely on the ground and of being connected with a water supply source and employed for irrigating tilled areas such as lawns, gardens and the like.
A sprinkler of this type basically includes a pipe having a number of differently oriented spray perforations or nozzles and pivotally mounted on a bearing block and driven to oscillate by the pressure of in-flowing water through a driving mechanism such as a turbine-type motor enclosed in a sealed box. The bearing block usually has an elongated shape and the box containing the driving mechanism is mounted at one end of the block in such a way as to be connected with the water supply source and at the same time to act as a driving support for at least one of the ends of the oscillating pipe. Mechanical control means, provided in the box containing the driving mechanism, are used to selectively define the surface of the area to be watered by setting the oscillation angle of the spray pipe accordingly. Further mechanical control means are provided inside the oscillating pipe itself for adjusting the surface of the area to be watered by blocking or choking part of the available spray nozzles, i.e. shutting off or blocking access of the water to selected of the nozzles.
German patent application No. 3,119,094 discloses a tubular sprinkler that is provided with a cylindrical slide valve that, through the use of a worm gear, i.e. wheel handle and related shank, can be caused to slide inside the spray pipe in order to choke or shut off part of its spray ports or nozzles. Such a device, however, has a major drawback in that it only enables spray nozzles to be shut off unidirectionally and in correspondence with that portion of the watering pipe in which the valve can actually be made to slide. This drawback causes an inconvenience in that the sprinkler itself must be displaced, or its orientation changed, each time special requirements arise for an area-limited watering action.